Get Law Of Friction Solved Examples Assignment Help Now

What is Solved Examples Based On The Law Of Friction

Example : Two planes AC and BC inclined at 60o and 30o to the horizontal meet at C.A load 1200 N rest on the inclined plane BC and is tied by a rope passing over a pulley to a block weighing W Newtons and resting on the plane AC as shown in Fig. (a). If the coefficient of friction between the load and the plane BC is 0.25 and that greatest value of W for the equilibrium of the system.

Solution

For the least value of W for equilibrium, the motion of 1200 N block is having impending motion downward. For such a case, the free body diagram of block are shown in Fig. (b).

Considering the 1200 N block:

Σ Force normal to plane = 0

N1 = 1200 cos 30o = 1039.23 N

From the law of friction, F1 = 0.25 N1

= 259.81 N

Σ Forces parallel to the plane CB = 0

T = – F1 + 1200 sin 30o

= – 259.81 + 1200 sin 30°s

= 340.19 N

Now consider the equilibrium of block of weight W:

Σ Forces normal to the plane AC = 0

N2 = W cos 60o = 0.5 W

From law of friction, when motion is impending

F2 = 0.2N2 = 0.1 W

Σ Forces parallel to the plane AC = 0

F2 + W sin 60o = T

W + W sin 60o = 340.19

W = 340.19/0.1 + sin60o

∴ W = 352.16 N

For the greatest value of W, the 1200 N block is on the verge of moving up the plane. For such a case, the free body diagrams of the blocks are as shown in Fig. (c).

Considering block of 1200 N,

N1 = 1200 cos 30o = 1039.23

F1 = µ1 N1 = 0.25 × 1039.23 = 259.81 N

Σ Forces parallel to plane CB = 0

T – 1200 sin 30° – F1 = 0

T = 1200 sin 30o + 259.81

= 859.81 N

Considering the block weighing W,

N2 = W cos 60° = 0.5 W

F2 = 0.2 N2 = 0.1 W

Σ Forces parallel to plane AB = 0

W sin 60o – T – F2 = 0

W sin 60o – F2 = T

W (sin 60° – 0.1) = 859.81

W = 1122.43 N

Email Based, Online Homework Assignment Help in Law Of Friction

Transtutors is the best place to get answers to all your doubts regarding law of friction. Transtutors has a vast panel of experienced in law of friction civil engineering tutorswho can explain the different concepts to you effectively. You can submit your school, college or university level homework or assignment to us and we will make sure that you get the answers related to law of friction